Question

a) y= 5 + 3x
2x - 3y = -8


b)x = 2y+7
x + y= -5
Determine os valores de x e y

Answer 1

a)y = 5 + 3 x
2 x - 3 y = -8

2 x - 3 (5 + 3 x) = - 8
2 x - 15 - 9 x = - 8
2 x - 9 x = - 8 + 15
- 7 x = 7
x = 7/-7
x = - 1
y = 5 + 3 x
y = 5 + 3 . - 1
y = 5 - 3
y = 2

b)x = 2 y + 7
x + y = - 5
2 y + 7  + y = - 5
3 y = - 5 - 7
3 y = - 12
y = -12/3
y = - 4
x = 2 y + 7
x = 2 . - 4 + 7
x = -8 + 7
x = - 1